1. Field of the Invention
The present invention discloses a method and composition for the treatment of bacterial infections by the use of a lysing enzyme blended with an appropriate carrier suitable for the treatment of the infection.
2. Description of the Prior Art
In the past, antibiotics have been used to treat various infections. The work of Selman Waksman in the introduction and production of Streptomycetes and Dr. Fleming""s discovery of penicillin, as well as the work of numerous others in the field of antibiotics, are well known. Over the years, there have been additions and chemical modifications to the xe2x80x9cbasicxe2x80x9d antibiotics in attempts to make them more powerful, or to treat people allergic to these antibiotics.
Others have found new uses for these antibiotics. U.S. Pat. No. 5,260,292 (Robinson et al.) discloses a topical treatment of acne with aminopenicillins. The method and composition for topically treating acne and acneiform dermal disorders includes applying an amount of an antibiotic selected from the group consisting of ampicillin, amoxicillin, other aminopenicillins, and cephalosporins, and derivatives and analogs thereof, effective to treat the acne and acneiform dermal disorders. U.S. Pat. No. 5,409,917 (Robinson et al.) discloses the topical treatment of acne with cephalosporins.
However, as more antibiotics have been prescribed or used at an ever increasing rate for a variety of illnesses, increasing numbers of bacteria have developed a resistance to antibiotics. Larger doses of stronger antibiotics are now being used to treat ever more resistant strains of bacteria. Multiple antibiotic resistant bacteria have consequently developed. The use of more antibiotics and the number of bacteria showing resistance has led to increasing the amount of time that the antibiotics need to be used. Broad, non-specific antibiotics, some of which have detrimental effects on the patient, are now being used more frequently. Also, antibiotics do not easily penetrate mucus linings. Additionally, the number of people allergic to antibiotics appears to be increasing.
Consequently, other efforts have been sought to first identify and then kill bacteria.
Attempts have been made to treat bacterial diseases by the use of bacteriophages. U.S. Pat. No. 5,688,501 (Merril, et al.) discloses a method for treating an infectious disease caused by bacteria in an animal with lytic or non-lytic bacteriophages that are specific for particular bacteria.
U.S. Pat. No. 4,957,686 (Norris) discloses a procedure of improved dental hygiene which comprises introducing into the mouth bacteriophages parasitic to bacteria which possess the property of readily adhering to the salivary pellicle.
It is to be noted that the direct introduction of bacteriophages into an animal to prevent or fight diseases has certain drawbacks. Specifically, the bacteria must be in the right growth phase for the phage to attach. Both the bacteria and the phage have to be in the correct and synchronized growth cycles. Additionally, there must be the right number of phages to attach to the bacteria; if there are too many or too few phages, there will either be no attachment or no production of the lysing enzyme. The phage must also be active enough. The phages are also inhibited by many things including bacterial debris from the organism it is going to attack. Further complicating the direct use of bacteriophage to treat bacterial infections is the possibility of immunological reactions, rendering the phage non-functional.
Consequently, others have explored the use of safer and more effective means to treat and prevent bacterial infections.
U.S. Pat. No. 5,604,109 (Fischetti et al.) relates to the rapid detection of Group A Streptococci in clinical specimens, through the enzymatic digestion by a semi-purified Group C streptococcal phage associated lysin enzyme. The lytic enzyme of this patent is used in U.S. Pat. No. 5,997,862 (Fischetti, et. al.), U.S. Pat. No. 5,985,271, (Fischetti et al.) and U.S. Pat. No. 6,017,528 (Fischetti et al.) which disclose the use of an oral delivery mode, such as a candy, chewing gum, lozenge, troche, tablet, a powder, an aerosol, a liquid or a liquid spray, containing a lysin enzyme produced by group C streptococcal bacteria infected with a C1 bacteriophage for the prophylactic and therapeutic treatment of Streptococcal A throat infections, commonly known as strep throat.
U.S. Pat. No. 6,056,955 (Fischetti et al.) discloses the topical treatment of streptococcal infections.
The method for obtaining and purifying the lytic enzyme produced by a bacteria infected with the bacteriophage is known in the art. Some recent evidence suggests that the phage enzyme that lyses the Streptococcus organism may actually be a bacterial enzyme that is used to construct the cell wall and the phage. While replicating in the bacterium, a phage gene product may cause the upregulation or derepression of bacterial enzyme for the purpose of releasing the bacteriophage. These bacterial enzymes may be tightly regulated by the bacterial cell and are used by the bacteria for the construction and assembly of the cell wall.
The use of these lytic enzymes for the prophylactic and therapeutic treatment of bacterial diseases, however, has not been explored, except by the inventors of the present invention. Consequently, the present invention discloses the extraction and use of a variety of bacterial phage associated lytic enzymes for the treatment of a wide variety of illnesses caused by bacterial infections.
The use of phage associated lytic enzymes produced by the infection of a bacteria with a bacteria specific phage has numerous advantages for the treatment of diseases. As the phage are targeted for specific bacteria, the lytic enzymes do not interfere with normal flora. Also, lytic phages primarily attack cell wall structures which are not affected by plasmid variation. The actions of the lytic enzymes are fast and do not depend on bacterial growth.
Lytic enzymes can be directed to the mucosal lining, where, in residence, they will be able to kill colonizing bacteria.
It is an object of the invention to use phage associated enzymes to prophylactically and therapeutically treat bacterial diseases.
The invention (which incorporates U.S. Pat. No. 5,604,109 in its entirety by reference) uses an enzyme produced by the bacterial organism after being infected with a particular bacteriophage as either a prophylactic treatment for preventing those who have been exposed to others who have the symptoms of an infection from getting sick, or as a therapeutic treatment for those who have already become ill from the infection. The present invention is based upon the discovery that phage lytic enzymes specific for bacteria infected with a specific phage can effectively and efficiently break down the cell wall of the bacterium in question. At the same time, the semipurified enzyme is lacking in proteolytic enzymatic activity and therefore non-destructive to mammalian proteins and tissues when present during the digestion of the bacterial cell wall. The same general technique used to produce and purify the lysin enzyme in U.S. Pat. 5,604,109 may be used to manufacture other lytic enzymes produced by bacteria infected with a bacteriophage specific for that bacteria. Depending on the bacteria, there may be variations in the growth media and conditions.
In one embodiment of the invention, the prophylactic and therapeutic treatment of a variety of illnesses caused by Streptococcal pneumoniae, Streptococcus fasciae, and Hemophilus influenza are disclosed. In another embodiment of the invention, gram negative bacterial infections caused by Listeria, Salmonella, E. coli, and Campylobacter, are treated by the use of lytic enzymes. These and other bacteria, which can infect the digestive system, can be treated by incorporating the lytic enzymes in suppository enemas, in syrups, or in other carriers to go directly to the site of the infection(s).
In another embodiment of the invention, lytic enzymes are incorporated into bandages to prevent or treat infections of bums and wounds. In yet another embodiment of the invention, the lytic enzymes of phage associated with Staphylococcus or Pseudomonas are incorporated into bandages to prevent or treat infections of burns and wounds.
Vaginal infections caused by Group B Streptococcus can cause premature births and subsequent complications resulting in neonatal sepsis. Lysin incorporated into tampons specific for group B strep would prevent infections of the neonate during birth without disturbing normal vaginal flora so that women would not be overcome by yeast infection as a result of antibiotic therapy.
In another embodiment of the invention, eye drops containing lytic enzymes of Hemophilus, Pseudomonas, and/or Staphylococcus can be used to directly treat eye infections. Treatment with lytic enzymes are faster and more expedient than with antibiotics.
In yet another embodiment of the invention the phage associated lytic enzyme is put into a carrier which is placed in an inhaler to treat or prevent the spread of diseases localized in the mucus lining of the oral cavity and lungs. Specific lytic enzymes for tuberculosis have been isolated and can be used.
In another embodiment of the invention the lytic enzyme is administered in the form of a candy, chewing gum, lozenge, troche, tablet, a powder, an aerosol, a liquid, a liquid spray, or toothpaste for the prevention or treatment of bacterial infections associated with upper respiratory tract illnesses.
In another embodiment of the invention, species specific lytic enzymes can be used in the treatment of bacterial infections associated with topical or dermatological infections, administered in the form of a topical ointment or cream. In another embodiment of the invention, the lytic enzyme would be administered in an aqueous form. In yet another embodiment of the invention, lysostaphin, the enzyme which lyses Staphylococcus aureus, can be included in the therapeutic agent. In a further embodiment of the invention, conventional antibiotics may be included in the therapeutic agent with the lytic enzyme, and with or without the presence of lysostaphin. More than one lytic enzyme may also be included in the prophylactic or therapeutic agent.